Thermal barrier coatings (TBCs) are used to protect hot section components of equipment such as aircraft engines, marine propulsion systems, and industrial gas turbines, from the extreme temperatures of the associated gas. Advanced thermal barrier coatings are needed to satisfy more demanding durability requirements, such as those of industrial gas turbines operating at turbine inlet temperatures of 2650° F. (1454° C.) and beyond.
Yttrium aluminum garnet (YAG) has desirable properties for a thermal barrier coating as previously disclosed, for example, in International Publication Number WO 2013/163058, published on Oct. 31, 2013, which also discloses methods of making such coatings. In some embodiments such coatings can be made to have significantly reduced thermal conductivity by doping with other elements.